Are there reasons for the seasons? It all starts with the sun. The sun shines on the earth and keeps it warm. We have day and night because the Earth spins on its axis and we spend part of each day facing the sun and part of the day facing away from it. But why are days longer in the summer than in the winter? The answer to this question is explained through an experiment using a pencil, an orange, and a flashlight. And when you see this, you’ll know the reasons for the seasons.